/* ==========================================
   全局样式与重置
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 主题色彩 */
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;

    /* 深色主题背景 */
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-tertiary: #1e293b;

    /* 文本颜色 */
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    /* 渐变 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
    --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.5);

    /* 过渡 */
    --transition-fast: 0.15s ease-in-out;
    --transition-normal: 0.3s ease-in-out;
    --transition-slow: 0.5s ease-in-out;

    /* 导航栏高度 */
    --nav-height: 70px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ==========================================
   导航栏
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 14, 26, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(59, 130, 246, 0.1);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(10, 14, 26, 0.98);
    box-shadow: var(--shadow-lg);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    height: var(--nav-height);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 0.5px;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all var(--transition-normal);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: var(--gradient-secondary);
    transition: transform var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
    background: rgba(59, 130, 246, 0.1);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: translateX(-50%) scaleX(1);
}

/* ==========================================
   主内容区
   ========================================== */
.main-content {
    margin-top: var(--nav-height);
    min-height: 100vh;
}

.slides-container {
    width: 100%;
    position: relative;
}

.slide {
    width: 100%;
    min-height: calc(100vh - var(--nav-height));
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 0;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.slide.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-content {
    width: 80%;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
}

.slide-image {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: var(--shadow-xl);
    transition: transform var(--transition-slow), box-shadow var(--transition-normal);
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.slide-image:hover {
    transform: translateY(-5px) scale(1.01);
    box-shadow: 0 25px 35px rgba(59, 130, 246, 0.3);
}

/* ==========================================
   进度指示器
   ========================================== */
.progress-indicator {
    position: fixed;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 900;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.progress-dots {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.progress-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(148, 163, 184, 0.3);
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
}

.progress-dot::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid transparent;
    transition: all var(--transition-normal);
}

.progress-dot:hover {
    background: rgba(148, 163, 184, 0.6);
    transform: scale(1.3);
}

.progress-dot.active {
    background: var(--primary-color);
    transform: scale(1.4);
}

.progress-dot.active::before {
    border-color: var(--primary-color);
    opacity: 0.3;
}

.progress-counter {
    background: rgba(17, 24, 39, 0.8);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.current-slide {
    color: var(--primary-color);
    font-size: 1.1rem;
}

/* ==========================================
   返回顶部按钮
   ========================================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 900;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--gradient-secondary);
    border: none;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.back-to-top:active {
    transform: translateY(-2px);
}

/* ==========================================
   页脚
   ========================================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid rgba(59, 130, 246, 0.2);
    padding: 3rem 2rem 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-section h4 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.footer-tagline {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.footer-section p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    padding-top: 2rem;
    border-top: 1px solid rgba(59, 130, 246, 0.1);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* ==========================================
   响应式设计
   ========================================== */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }

    .nav-link {
        padding: 0.4rem 0.6rem;
        font-size: 0.85rem;
    }

    .logo-text {
        font-size: 0.95rem;
    }

    .slide {
        padding: 1.5rem 0;
        min-height: auto;
    }

    .slide-content {
        width: 85%;
    }

    .slide-image {
        border-radius: 8px;
    }

    .progress-indicator {
        right: 0.5rem;
        gap: 1rem;
    }

    .progress-dots {
        gap: 0.5rem;
    }

    .progress-dot {
        width: 7px;
        height: 7px;
    }

    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 45px;
        height: 45px;
    }

    .footer {
        padding: 2rem 1rem 1rem;
    }
}

@media (max-width: 480px) {
    .nav-container {
        padding: 0 1rem;
    }

    .nav-links {
        gap: 0.5rem;
    }

    .nav-link {
        padding: 0.3rem 0.5rem;
        font-size: 0.75rem;
    }

    .logo-text {
        font-size: 0.85rem;
    }

    .slide {
        padding: 1rem 0;
    }

    .slide-content {
        width: 90%;
    }

    .progress-indicator {
        right: 0.3rem;
    }

    .progress-counter {
        font-size: 0.75rem;
        padding: 0.4rem 0.8rem;
    }

    .progress-dot {
        width: 6px;
        height: 6px;
    }
}

/* ==========================================
   滚动条样式
   ========================================== */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* ==========================================
   加载动画
   ========================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================
   打印样式
   ========================================== */
@media print {

    .navbar,
    .progress-indicator,
    .back-to-top,
    .footer {
        display: none;
    }

    .slide {
        page-break-after: always;
        min-height: auto;
    }

    .slide-image {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}